CN118151433A

CN118151433A - Backlight unit and display device including the same

Info

Publication number: CN118151433A
Application number: CN202311600605.XA
Authority: CN
Inventors: 金诚一; 金宗贤; 吴领民
Original assignee: LG Display Co Ltd
Current assignee: LG Display Co Ltd
Priority date: 2022-12-05
Filing date: 2023-11-28
Publication date: 2024-06-07
Also published as: US20240184032A1; KR20240083467A

Abstract

A display device including a display panel for displaying an image and a backlight unit, the backlight unit comprising: a first light source package configured to output light; a second light source package configured to output light, the second light source package facing the first light source package; and a light guide plate disposed between the first light source package and the second light source package, the light guide plate including a pattern protruding from a bottom surface of the light guide plate. Further, the pattern faces the first light source package or the second light source package and includes at least one inclined surface having an inclination angle with respect to the bottom surface of the light guide plate.

Description

Backlight unit and display device including the same

Cross Reference to Related Applications

The present application claims priority from korean patent application No. 10-2022-0167635 filed on month 5 of 2022, 12, which is incorporated herein by reference in its entirety for all purposes.

Technical Field

The present invention relates to a backlight unit and a display device including the same.

Background

With the development of information society, various forms of display devices are also being developed. In recent years, various types of display devices such as a Liquid Crystal Display (LCD), a Plasma Display Panel (PDP), and an organic electroluminescent display (OLED) have been applied.

Typical display devices do not limit viewing angle. For example, OLEDs and LCDs can have a wide viewing angle, which is generally desirable in most cases, but in some cases may be undesirable. However, there is an increasing demand for display devices having limited viewing angles for such considerations as security, privacy, and information security. For example, when using a display device used as an in-vehicle information medium, it may be desirable to limit the viewing angle of a driver to ensure safe driving and avoid distraction while providing a high quality image to a passenger sitting in a front passenger seat.

Disclosure of Invention

Embodiments of the present disclosure provide a backlight unit capable of effectively limiting a viewing angle and a display device including the same.

The backlight unit according to an embodiment of the present disclosure may include: a first light source package generating light; a second light source package generating light and facing the first light source package; and a light guide plate disposed between the first light source package and the second light source package and including a pattern protruding on a bottom surface thereof.

The pattern may face the first light source package or the second light source package and include at least one inclined surface having a predetermined inclination angle with respect to the bottom surface.

The pattern may include: a first pattern formed in a first region adjacent to the first light source package and including a first slope facing the first light source package; and a second pattern formed in a second region adjacent to the second light source package and including a second slope facing the second light source package.

The first pattern and the second pattern may have mirror image shapes or may be symmetrically arranged based on a boundary between the first region and the second region.

The first pattern and the second pattern may have a cross section of an asymmetric trapezoid shape having the inclined plane as a vertical side.

Light incident to the light guide plate from the first light source package may be refracted by the first slope of the first pattern and emitted through the top surface in the first region, and light incident to the light guide plate from the second light source package may be refracted by the second slope of the second pattern and emitted through the top surface in the second region.

The first and second regions may be adjacent to each other, and the first and second patterns may be disposed adjacent to each other at a boundary between the first and second regions.

The first region and the second region may be spaced apart from each other, a third region may be formed between the first region and the second region, and the first pattern and the second pattern may be spaced apart from each other.

The backlight unit may further include a third light source package disposed on one side of the third region.

The pattern may be formed in the third region and include a third pattern including a third slope facing the first light source package or the second light source package.

The third inclined surface may have an inclination angle smaller than those of the first inclined surface and the second inclined surface.

The backlight unit may further include a fourth pattern protruding in a dome or dome-shaped form on the top surface of the light guide plate.

The thickness of the light guide plate at edges adjacent to the first and second light source packages may be greater than the thickness at a central region thereof.

A display device according to an embodiment of the present disclosure includes: a display panel including pixels and displaying an image; a first backlight unit disposed under the display panel and emitting light to the display panel; a second backlight unit disposed under the first backlight unit; and an optical path control pattern disposed between the first and second backlight units and including a light shielding pattern to control the light to be emitted in a narrow angle range.

The first backlight unit may include: a first light source package generating light; a second light source package generating light and facing the first light source package; and a first light guide plate disposed between the first light source package and the second light source package and including a pattern protruding on a bottom surface thereof.

The display device may include: a third light source package generating light; and a second light guide plate disposed on one side of the third light source package.

Light incident to the first light guide plate from the first light source package may be refracted by the first slope of the first pattern and emitted through the top surface in the first region, light incident to the first light guide plate from the second light source package may be refracted by the second slope of the second pattern and emitted through the top surface in the second region, and light incident to the second light guide plate from the third light source package may be emitted through the top surface of the second light guide plate and then emitted in a narrow angle range through the light path control patterns in the first region and the second region.

The display device may further include a third region formed between the first region and the second region, and the first backlight unit may further include a fourth light source package disposed on one side of the third region.

Light incident to the first light guide plate from the fourth light source package may be emitted through a top surface of the first light guide plate in the third region.

The pattern may include a third pattern formed in a third region between the first region and the second region, and include a third slope facing the first backlight unit or the second backlight unit.

Drawings

The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a cross-sectional view of a display device according to an embodiment of the present disclosure;

fig. 2 is a rear perspective view schematically illustrating a structure of a first light guide plate according to an embodiment of the present disclosure;

fig. 3 is a cross-sectional view schematically illustrating a structure of a first backlight unit according to an embodiment of the present disclosure;

fig. 4 to 7 are cross-sectional views illustrating various modes of a display device according to an embodiment of the present disclosure;

fig. 8 is a cross-sectional view schematically illustrating a structure of a first backlight unit according to another embodiment of the present disclosure;

Fig. 9 is a perspective view schematically illustrating a structure of a first backlight unit according to another embodiment of the present disclosure;

fig. 10 is a cross-sectional view schematically illustrating a structure of a first backlight unit according to another embodiment of the present disclosure;

fig. 11 to 16 are cross-sectional views illustrating various modes of a display device according to another embodiment of the present disclosure; and

Fig. 17 is a cross-sectional view schematically illustrating a structure of a first backlight unit according to another embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. In the specification, when an element (or region, layer, section, etc.) is referred to as being "on" another element, "connected to" or "coupled to" the other element, it can be directly connected/coupled to the other element or a third element can be disposed therebetween.

Like reference numerals refer to like parts. In addition, in the drawings, thicknesses, ratios, and sizes of components are exaggerated for effective description of technical contents. The expression "and/or" is considered to include one or more combinations that may be defined by the associated components.

The terms "first," "second," and the like are used to describe various components, but the components should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the singular is intended to include the plural unless the context clearly indicates otherwise.

Terms such as "below … …," "lower," "above … …," "upper" are used to describe the relationship of the components depicted in the figures. These terms are relative concepts and are described based on the directions indicated on the drawings.

It will be further understood that the terms "comprises," "comprising," "includes," and the like are intended to specify the presence of stated features, amounts, steps, operations, components, portions, or combinations thereof, but are not intended to preclude the presence or addition of one or more other features, amounts, steps, operations, components, portions, or combinations thereof.

Features of various embodiments of the disclosure may be partially or fully coupled or combined with each other and may be interlocked and operated in technically different manners, and these embodiments may be performed independently or in association with each other.

Fig. 1 is a cross-sectional view of a display device according to an embodiment. Fig. 2 is a rear perspective view schematically illustrating a structure of the first light guide plate in fig. 1 according to an embodiment, and fig. 3 is a cross-sectional view schematically substantially illustrating a structure of the first backlight unit in fig. 1 according to an embodiment.

Referring to fig. 1, a display device 1 according to an embodiment may include a display panel 110 including pixels to display an image, and first and second backlight units 120 and 130 disposed under the display panel 110 to emit light toward a front surface of the display panel 110. In addition, the display device 1 may further include a panel guide, a top case, a bottom cover, etc. to accommodate and fix the display panel 110 and the first and second backlight units 120 and 130. Further, the display device 1 may include: a display panel including a plurality of subpixels, a plurality of data lines, and a plurality of gate lines; a data driver configured to supply a data voltage to the data line; a gate driver configured to supply a scan signal to the gate lines; and a controller (e.g., a timing controller) configured to control the data driver and the gate driver.

The display panel 110 may be a liquid crystal panel, which may include a lower substrate and an upper substrate that are bonded to face each other with a liquid crystal layer interposed therebetween.

The lower substrate may include gate and data lines arranged to cross each other and liquid crystal cells formed at crossing regions of the gate and data lines. In an embodiment, the liquid crystal cells may be arranged in a matrix form on the lower substrate. The liquid crystal cell may include a Thin Film Transistor (TFT) disposed at an intersection of the gate line and the data line and a pixel electrode receiving a data voltage supplied via the thin film transistor when the thin film transistor is turned on.

The upper substrate may include: a color filter for realizing a plurality of colors including red, green, and blue; a black matrix (which defines a color filter and blocks light passing through the liquid crystal layer); and a common electrode for applying a voltage to the liquid crystal layer.

The common electrode may be formed on the upper substrate in a vertical electric field driving method such as a Twisted Nematic (TN) mode and a Vertical Alignment (VA) mode, and may be formed on the lower substrate with the pixel electrode in a horizontal electric field driving method such as an in-plane switching (IPS) mode and a Fringe Field Switching (FFS) mode.

The liquid crystal cell is driven by a potential difference between a data voltage supplied to the pixel electrode through the data line and a common voltage supplied to the common electrode, and generates an electric field to adjust an amount of light transmitted through the display panel 110.

The first and second backlight units 120 and 130 are disposed under the display panel 110 to provide light to the display panel 110. The first backlight unit 120 is disposed under the display panel 110, and the second backlight unit 130 may be disposed under the first backlight unit 120.

The first backlight unit 120 may include a first light source package 121, a second light source package 122, and a first light guide plate 123.

The first and second light source packages 121 and 122 may be powered and driven by an external power source to generate light. The first and second light source packages 121 and 122 may generate light using various light sources such as Cold Cathode Fluorescent Lamps (CCFLs), external Electrode Fluorescent Lamps (EEFLs), hot Cathode Fluorescent Lamps (HCFLs), and Light Emitting Diodes (LEDs).

The first and second light source packages 121 and 122 are arranged to face each other. In this case, the first and second light source packages 121 and 122 may be disposed to face at least one side of the first light guide plate 123. For example, the first light source package 121 may be disposed on one side of the first light guide plate 123, and the second light source package 122 may be disposed on the other side of the first light guide plate 123, facing the first light source package 121. For example, the first and second light source packages 121 and 122 may be disposed on opposite sides of the first light guide plate 123, but the embodiment is not limited thereto. Accordingly, light emitted from the first and second light source packages 121 and 122 may be incident on a side surface of the first light guide plate 123 (e.g., an edge-lit backlight).

The first light guide plate 123 is interposed between the first and second light source packages 121 and 122. For example, the first light guide plate 123 is disposed between the first and second light source packages 121 and 122, facing the first and second light source packages 121 and 122, to guide light incident from the first and second light source packages 121 and 122 and emit light through the top surface.

In an embodiment, the first light guide plate 123 may be made of a transparent material, such as a plastic material selected from the group consisting of polymethyl methacrylate (PMMA) and Polycarbonate (PC). However, the material of the first light guide plate 123 is not limited to the above-described material, and the first light guide plate 123 may be manufactured of other materials.

Referring to fig. 2 and 3, the first light guide plate 123 may include a first pattern 123a and a second pattern 123b protruding from a bottom surface of the first light guide plate 123. The first pattern 123a and the second pattern 123b may be formed in a relief manner on the bottom surface of the first light guide plate 123 by a molding or printing method.

In an embodiment, the first pattern 123a and the second pattern 123b may be formed on the entire bottom surface of the first light guide plate 123 or in at least one region or a partial region. For example, the first pattern 123a may be formed in a first region A1 adjacent to the first light source package 121 on the first light guide plate 123. The second pattern 123b may be formed in a second region A2 adjacent to the second light source package 122 on the first light guide plate 123. In this case, the first and second areas A1 and A2 are defined as areas adjacent to each other, and the first pattern 123a and the second pattern 123b may be disposed adjacent to each other on the first light guide plate 123 at a boundary between the first and second areas A1 and A2.

The first pattern 123a and the second pattern 123b may be identical or similar in shape to each other. For example, the first pattern 123a and the second pattern 123b may have mirror shapes based on a boundary between the first and second areas A1 and A2 (e.g., the first pattern 123a and the second pattern 123b may be disposed in a symmetrical arrangement based on a boundary between the first area A1 and the second area A2).

The first pattern 123a may face the first backlight unit 120 and include at least one first slope a1 having a predetermined inclination angle with respect to the bottom surface of the first light guide plate 123. Similarly, the second pattern 123b may face the second light source package 122 and include at least one second inclined surface a2 having a predetermined inclination angle with respect to the bottom surface of the first light guide plate 123. In the embodiment, the inclination angle θ is about 30 ° to 50 °, and preferably 40 °, but is not limited thereto.

In the present embodiment, the cross sections of the first pattern 123a and the second pattern 123b may each have an asymmetric trapezoidal shape with the inclined surfaces a1 and a2 as inclined sides. However, the outline is not limited to the present embodiment, and the cross sections of the first pattern 123a and the second pattern 123b may have various shapes, such as an asymmetric triangle or a polygon having the above-described inclined surfaces a1 and a2 as sides.

The first pattern 123a and the second pattern 123b are spaced apart at similar intervals, and may have an elongated shape extending parallel to sides adjacent to the light source packages 121 and 122. However, without being limited to the present embodiment, the first pattern 123a and the second pattern 123b may have long or short stripes or dots arranged to be regularly or irregularly spaced or dispersed.

The first and second patterns 123a and 123b may have a height h of about 40 to 60 μm, and preferably 50 μm. The first and second patterns 123a and 123b may have a width w of about 110 to 130 μm, and preferably 120 μm. The first and second patterns 123a and 123b may have a pitch g of about 40 to 60 μm, and preferably 50 μm. Meanwhile, when the first pattern 123a and the second pattern 123b have an asymmetric trapezoidal shape as depicted, the width f of the narrow lower side of the trapezoid may be about 20 to 40 μm, and preferably 30 μm. However, the values of the first pattern 123a and the second pattern 123b are not limited to those described in the present embodiment.

Light incident on the first light guide plate 123 from the first and second light source packages 121 and 122 may be controlled by the first and second patterns 123a and 123b formed on the bottom surface thereof to emit light at a controlled area. Specifically, the light emitted from the first light source package 121 and guided through the first light guide plate 123 is refracted by the first inclined surface a1 of the first pattern 123a and emitted through the top surface. That is, light emitted from the first light source package 121 is prevented from being guided to the second area A2. As a result, light emission from the second area A2 can be restricted.

Similarly, light emitted from the second light source package 122 and guided through the first light guide plate 123 is refracted by the second inclined surface a2 of the second pattern 123b and emitted through the top surface, and is prevented from being guided to the first region A1. As a result, light emission from the first area A1 can be restricted.

According to an embodiment, the first backlight unit 120 may further include a first diffusion sheet, a first prism sheet, and a first light control film.

For example, the first diffusion sheet and the first prism sheet may be further disposed on the first light guide plate 123. The first diffusion sheet may diffuse the light emitted from the first light guide plate 123 to provide brightness uniformity according to the viewing angle. The first diffusion sheet may be formed of polyethylene terephthalate (PET) or Polycarbonate (PC) resin, and may additionally include a particle coating layer serving as diffusion. The first prism sheet may concentrate the direction of light emitted from the first light guide plate 123 or the first diffusion sheet to an orthogonal direction near the display panel 110, thereby improving front brightness of the display panel 110.

The first light control film LCF may be placed on the first prism sheet. The first light control film LCF may control the light emission profile of the first backlight unit 120 in combination with the first pattern 123 a. For example, the first light control film may control the horizontal and/or vertical viewing angle of the light emitted from the first backlight unit 120 to have a narrow viewing angle.

Below the first backlight unit 120, a second backlight unit 130 is arranged (e.g., two separate backlight units may be configured in a stacked arrangement). The second backlight unit 130 may include a third light source package 131 and a second light guide plate 132.

The third light source package 131 may be driven by a power supply supplied from the outside to generate light. The third light source package 131 may generate light using various light sources such as a Cold Cathode Fluorescent Lamp (CCFL), an External Electrode Fluorescent Lamp (EEFL), a Hot Cathode Fluorescent Lamp (HCFL), and a Light Emitting Diode (LED).

The third light source package 131 is disposed to face at least one side of the second light guide plate 132. Accordingly, the light emitted from the third light source package 131 may be incident on a side surface of the second light guide plate 132 (e.g., an edge-lit backlight unit). In an embodiment, the third light source package 131 may be disposed on the same side as one of the first and second light source packages 121 and 122. For example, the first light source packages 121 may be disposed on the same side as the display device 1. However, the present embodiment is not limited thereto. Further, according to another embodiment, the third light source packages 131 may be disposed at more than one side of the second light guide plate 132 (e.g., the light sources are disposed at opposite sides of the second light guide plate 132).

The second light guide plate 132 is disposed to face the third light source package 131, and guides light incident from the third light source package 131 to be emitted through the top surface. In an embodiment, the first light guide plate 132 may be made of a transparent material, such as a plastic material selected from the group consisting of polymethyl methacrylate (PMMA) and Polycarbonate (PC).

According to an embodiment, the second backlight unit 130 may further include a second light control film.

For example, a second light control film may be additionally disposed on the second light guide plate 132. The second light control film may control the light emission profile of the second backlight unit 130. For example, the first light control film may control the horizontal and/or vertical viewing angle of the light emitted from the second backlight unit 130 to have a narrow viewing angle.

The light path control pattern 140 may be disposed between the first and second backlight units 120 and 130. The optical path control pattern 140 may include light shielding patterns 142 patterned at regular intervals within the transmission layer 141.

The transmission layer 141 may protect the light shielding pattern 142 and flatten the top surface of the light path control pattern 140 by removing any unevenness caused by the light shielding pattern 142 (e.g., the transmission layer 141 may be used as a type of planarization layer). The transmission layer 141 may be made of a transparent material having high transmittance, such as polyethylene terephthalate (PET), polycarbonate (PC), optically transparent adhesive (OCA), ultraviolet (UV) resin, photoresist resin, polyurethane resin, acrylic resin, silicon oxide, or any combination of two or more thereof. The transmission layer 141 may allow light incident from the second backlight unit 130 to pass in the opposite direction, for example, to the first backlight unit 120.

The light shielding pattern 142 may have a bar shape elongated in the thickness direction of the light path control pattern 140. The width of the light shielding pattern 142 in the thickness direction may be constant or variable. For example, the light shielding pattern 142 may have a cross section of a trapezoid having a wide width at one side adjacent to the second backlight unit 130 and a narrow width at the opposite side adjacent to the first backlight unit 120, the wide width being wider than the narrow width, as shown in fig. 1. However, the outline is not limited to the present embodiment, and in various other embodiments, the light shielding pattern 142 may be formed in a uniform width or an inverted trapezoidal shape.

The light shielding pattern 142 may be formed in the shape of a concave groove that penetrates the light path control pattern 140 at all times or does not penetrate the light path control pattern 140 (e.g., a groove that extends partially into the light path control pattern 140). The light blocking pattern 142 may be made of a colored light absorbing material. For example, the light shielding pattern 142 may be composed of electronic ink containing black particles and the light shielding pattern 142 may block light emitted from the third light source package 131.

Light incident on the light path control pattern 140 passes through gaps between the light shielding patterns 142 to the front surface and is blocked at the side surfaces by the light shielding patterns 142. Accordingly, the light control entering the light path control pattern 140 can be controlled within a narrow angle range with respect to the front surface of the light path control pattern 140.

Hereinafter, an embodiment in which the side view angle of the display device 1 is controlled via the first backlight unit 120 configured as described above is described.

Fig. 4 to 7 are cross-sectional views illustrating various modes of a display device according to an embodiment. In the embodiment of fig. 4 to 7, the display device 1 is mounted in a vehicle. The display device 1 may be integrally or detachably mounted on the dashboard of the vehicle or in the center console of the vehicle. In particular, in the present embodiment, the display device 1 may be mounted on the instrument panel in an area other than the front face of the driver seat in which the instrument panel is displayed (for example, the display device 1 may be located in the front face of the passenger seat or in the center area of the instrument panel).

In the present embodiment, the display apparatus 1 may display a Graphical User Interface (GUI) corresponding to navigation, video content, and audio content in response to a driving state and/or a user request.

Specifically, the display apparatus 1 may be selectively operated in the privacy viewing mode when the vehicle is running. For example, the display apparatus 1 may operate in a privacy viewing mode when displaying videos or other contents, which may disperse the attention of the driver while driving. In contrast, the display apparatus 1 may operate in the shared viewing mode during a non-driving period of the vehicle (for example, in a case where both the driver and the passenger are able to view the image on the display). For example, the display apparatus 1 may dynamically switch between a shared viewing mode with a wide viewing angle and a private viewing mode with a narrow viewing angle. The display apparatus 1 can operate in the shared viewing mode even when the vehicle is operating. For example, the display apparatus 1 may operate in the shared viewing mode when displaying a video (such as navigation) that is considered to be helpful for the user to drive or when providing emergency or safety information.

Referring to part (a) of fig. 4, when the display apparatus 1 operates in a first mode (e.g., a shared viewing mode), the first and second light source packages 121 and 122 of the first backlight unit 120 are turned on. The third light source package 131 of the second backlight unit 130 may be turned off.

The light generated from the first light source package 121 is guided to the first area A1 through the first light guide plate 123 while being blocked from entering the second area A2 by the first pattern 123 a. Similarly, the light generated from the second light source package 122 is guided to the second area A2 through the first light guide plate 123, and is blocked from entering the first area A1 by the second pattern 123 b.

As a result, light generated from the first and second light source packages 121 and 122 is emitted through the top surfaces in both the first and second areas A1 and A2, and an image may be displayed through the entire area of the first display panel 110. Accordingly, when the first and second light source packages 121 and 122 are turned on, a shared viewing mode may be implemented such that the viewing angle is completely opened to the front and side of the display apparatus 1, as shown in part (b) of fig. 4. In the shared viewing mode, the user in both the driver seat and the passenger seat can view all the images displayed on the entire area of the display apparatus 1, and can provide a wide viewing angle.

Referring to part (a) of fig. 5, when the display apparatus 1 operates in the second mode (e.g., the privacy viewing mode), the third light source package 131 of the second backlight unit 130 is turned on. The first and second light source packages 121 and 122 of the first backlight unit 120 may be turned off.

The light generated from the third light source package 131 may be guided through the second light guide plate 132 and emitted from the front surface of the second light guide plate 132. The emitted light may be controlled within a narrow viewing angle range by the light shielding pattern 142, passing through the light path control pattern 140. As a result, a first privacy mode can be achieved in which the view of the front of the display device 1 is open, while the view of the sides is limited, as shown in part (b) of fig. 5, to provide a narrow view angle (for example, this helps reduce reflection on other objects (e.g. windows), which is particularly useful during night driving, but the driver can still view the image on the display, which can also prevent people outside the vehicle from easily viewing what is being displayed). Further, the privacy viewing mode may be enabled based on a user request, but may also be automatically enabled based on a preset condition, for example, when an ambient light below a threshold is sensed at a specific time such as after sunset, or when a vehicle traveling speed is faster than a preset speed limit, or the like, but the embodiment is not limited thereto.

In the first privacy mode, the user in both the driver seat and the passenger seat can view only the image displayed on the front face of the display apparatus 1. That is, the user in the driver seat can only view a partial image (e.g., navigation, instrument panel, etc.) displayed on the display device 1 from the front surface of the driver seat. In other words, the user in the passenger seat may only see a portion of the content displayed in front of the driver, and the passenger's field of view may be limited.

Referring to part (a) of fig. 6, when the display apparatus 1 operates in the third mode, the second light source packages 122 of the first backlight unit 120 and the third light source packages 131 of the second backlight unit 130 are turned on. The first light source package 121 of the first backlight unit 120 may be turned off.

Similarly, the light generated from the second light source package 122 may be guided to the second area A2 through the first light guide plate 123 while being prevented from entering the first area A1. Accordingly, the light generated from the second light source package 122 is emitted through the top surface in the second area A2. Accordingly, in the second area A2, the viewing angle can be completely opened to the front and side of the display device 1. For example, the second area A2 may have a wide viewing angle, and the second area A1 has a narrow viewing angle. The third mode may be referred to as a mixed viewing mode, wherein the driver is provided with a private viewing mode and the passenger is provided with a shared viewing mode.

The light generated from the third light source package 131 may be guided through the second light guide plate 132 and emitted through the top surface of the second light guide plate 132. The emitted light may be controlled within a narrow angle range by the light shielding pattern 142, passing through the light path control pattern 140. Accordingly, as shown in part (b) of fig. 6, in the first area A1, the viewing angle of the front face of the display device 1 may be open, and the viewing angle of the side face may be limited (for example, only a narrow viewing angle may be provided for the driver).

Accordingly, the third mode is a partial privacy mode mixed viewing mode (third privacy mode) in which the display apparatus 1 can operate such that the privacy mode having a narrow viewing angle is realized only in the first area A1, and the second area A2 can be operated with a wide viewing angle.

Referring to part (a) of fig. 7, when the display apparatus 1 operates in a fourth mode (e.g., another type of mixed viewing mode or partial privacy mode), the first light source packages 121 of the first backlight unit 120 and the third light source packages 131 of the second backlight unit 120 are turned on. The second light source package 122 of the first backlight unit 120 may be turned off.

Light generated from the first light source package 121 is guided to the first area A1 through the first light guide plate 123, and prevented from entering the second area A2. Accordingly, light emitted from the first light source package 121 is emitted through the top surface in the second area A1. Accordingly, in the first area A1, the viewing angle can be completely opened to the front and side of the display device 1, and a wide viewing angle can be provided to the driver.

The light generated from the third light source package 131 may be guided through the second light guide plate 132 and emitted through the top surface of the second light guide plate 132. The emitted light may be controlled within a narrow viewing angle range by the light shielding pattern 142, passing through the light path control pattern 140. Accordingly, as shown in part (b) of fig. 7, in the second area A2, the view angle of the front face of the display device 1 may be open, and the view angle of the side face may be limited (a narrow view angle may be provided for the passenger, which helps to avoid distraction of the driver).

Thus, the fourth mode is a partial privacy mode or a mixed viewing mode (fourth privacy mode), in which the display apparatus 1 is operable such that the privacy mode is implemented only in the second area A2. Thus, for a particular configuration of stacked backlight units with an optical path control pattern disposed therebetween, the controller in the display device 1 may control the backlight units to provide at least four different viewing modes, for example: 1) A shared viewing mode having a wide viewing angle for both the first area A1 and the second area A2; 2) A private viewing mode having a narrow viewing angle for both the first area A1 and the second area A2; 3) A first mixed viewing mode having a narrow viewing angle for the first region A1 and a wide viewing angle for the second region A2; and 4) a second mixed viewing mode having a wide viewing angle for the first domain A1 and a narrow viewing angle for the second region A2. In this way, the display device 1 can selectively switch between four different viewing modes using the same liquid crystal display.

Furthermore, according to another embodiment, the display device 1 may provide a high brightness mode, wherein the first light source package 121, the second light source package 122 and the third light source package 131 are all turned on simultaneously (e.g. when the ambient light is bright, such as may be helpful in a sunny day or an emergency).

Fig. 8 is a cross-sectional view schematically showing the structure of a first backlight unit according to another embodiment.

Referring to fig. 8, the first backlight unit 220 may include a first light source package 221, a second light source package 222, and a first light guide plate

The first light guide plate 223 is interposed between the first and second light source packages 221 and 222. The first light guide plate 223 is disposed between the first and second light source packages 221 and 222, facing the first and second light source packages 221 and 222, to guide light incident from the first and second light source packages 221 and 222 and emit light through the top surface.

The first light guide plate 223 may include a first pattern 223a and a second pattern 223b, the first pattern 223a and the second pattern 223b protruding from a bottom surface of the first light guide plate 223. The first pattern 223a and the second pattern 223b may be formed in a relief manner on the bottom surface of the first light guide plate 223 by a molding or printing method. According to another embodiment, the first pattern 223a and the second pattern 223b may be formed as a series of grooves etched into the bottom surface of the first light guide plate 223.

In an embodiment, the first pattern 223a and the second pattern 223b may be formed on the entire bottom surface of the first light guide plate 223 or in at least one region. For example, the first pattern 223a and the second pattern 223b may be formed in a central region of the rear surface of the first light guide plate 223. However, the present embodiment is not limited thereto.

The first pattern 223a may be formed in a first area A1 adjacent to the first light source package 221 on the first light guide plate 223. The second pattern 223b may be formed in a second region A2 adjacent to the second light source package 222 on the first light guide plate 223. The first pattern 223a and the second pattern 223b may be identical or similar in shape to each other. For example, the first pattern 223a and the second pattern 223b may have mirror image shapes or symmetrical arrangements based on the boundary between the first and second areas A1 and A2.

The first pattern 223a may face the first light source package 221 and include at least one first inclined plane a1 having a predetermined inclination angle with the bottom surface of the first light guide plate 223. Similarly, the second pattern 223b may face the second light source package 222 and include at least one second inclined surface a2 having a predetermined inclination angle with respect to the bottom surface of the first light guide plate 223. In an embodiment, the inclination angle is about 30 ° to 50 °, and preferably 40 °, but is not limited thereto.

In the present embodiment, the cross sections of the first pattern 223a and the second pattern 223b may be asymmetric trapezoids with the above-described inclined planes a1 and a2 as the vertical sides. However, the outline is not limited to the present embodiment, and the cross sections of the first pattern 223a and the second pattern 223b may have various shapes, such as an asymmetric triangle or a polygon with the above-described inclined planes a1 and a2 as vertical sides.

The first pattern 223a and the second pattern 223b are spaced apart at similar intervals, and may have an elongated shape extending parallel to sides adjacent to the light source packages 221 and 222. However, not limited to the present embodiment, the first pattern 223a and the second pattern 223b may have long or short stripes or dots arranged to be regularly or irregularly spaced or dispersed.

In the embodiment of fig. 8, the first light guide plate 123 further includes a third pattern 223c, the third pattern 223c being formed in a third area A3 between the first and second areas A1 and A2 on the rear surface of the first light guide plate 223. In an embodiment, the third region A3 may include a central region of the first light guide plate 123. The first region A1, the third region A3, and the second region A2 may be defined as adjacent regions.

The third pattern 223c may be identical or similar in shape to the first and second patterns 223a and 223 b. For example, some of the third patterns 223c may have the same shape as the first patterns 223a, and the remaining patterns may have the same shape as the second patterns 223 b.

The inclination angle of the third inclined plane a3 of the third pattern 223c may be smaller than the inclination angles of the inclined planes a1 and a2 of the first and second patterns 223a and 223 b. For example, the inclination angle θ of the third inclined surface a3 of the third pattern 223c may be about 25 ° to 45 °, preferably about 35 °, but is not limited thereto.

The third pattern 223c may be formed smaller than the first and second patterns 223a and 223b and have a narrow gap. For example, the third pattern 223c may have a height h of about 30 μm to 50 μm, preferably 40 μm, with a gap g between about 30 μm to 50 μm, preferably 40 μm.

Light incident on the first light guide plate 223 from the first and second light source packages 221 and 222 may be controlled by the first and second patterns 223a and 223b formed on the bottom surface thereof to be emitted in a controlled area. Specifically, the light emitted from the first light source package 221 and guided through the first light guide plate 223 is refracted by the first inclined plane a1 of the first pattern 223a and emitted through the top surface. That is, light emitted from the first light source package 221 is prevented from being guided to the second area A2. As a result, light emission from the second area A2 can be restricted.

Similarly, light emitted from the second light source package 222 and guided through the first light guide plate 223 is refracted by the second inclined surface a2 of the second pattern 223b and emitted through the top surface, and is prevented from being guided to the first area A1. As a result, light emission from the first area A1 can be restricted.

In the embodiment of fig. 8, light incident on the first light guide plate 223 from the first and second light source packages 221 and 222 is also refracted by the third inclined plane a3 of the third pattern 223c and emitted through the top surface.

Light is emitted orthogonal to the top surface in the first area A1 or the second area A2. In the third region A3, light may be emitted in a lateral direction with respect to the top surface due to the small inclination angle of the third slope A3 of the third pattern 223 c. As a result, it is possible to improve the problem of perceiving an image as having discontinuity at the boundary between the first and second areas A1 and A2 due to the blocking of the light guide by the first and second patterns 223a and 223 b.

Fig. 9 is a perspective view schematically showing the structure of a first backlight unit according to another embodiment. Fig. 10 is a cross-sectional view schematically showing the structure of a first backlight unit according to another embodiment.

Referring to fig. 9 and 10, the first backlight unit 320 may include a first light source package 321, a second light source package 322, and a first light guide plate 323.

The first light guide plate 323 is interposed between the first and second light source packages 321 and 322. The first light guide plate 323 is disposed between the first and second light source packages 321 and 322, facing the first and second light source packages 321 and 322, to guide light incident from the first and second light source packages 321 and 322 and emit light through the top surface.

The first light guide plate 323 may include a first pattern 323a and a second pattern 323b formed to protrude on a bottom surface thereof. The first pattern 323a and the second pattern 323b may be formed in a relief manner on the bottom surface of the first light guide plate 323 by a molding or printing method.

In the embodiment of fig. 9 and 10, the first pattern 323a may be formed in a first region A1 adjacent to the first light source package 321 on the first light guide plate 323. The second pattern 323b may be formed in a second region A2 adjacent to the second light source package 322 on the first light guide plate 323. Here, the first and second areas A1 and A2 are defined as sufficiently spaced apart areas, and a third area A3 may be defined between the first and second areas A1 and A2. The first pattern 323a and the second pattern 323b are formed to be sufficiently spaced apart from each other because the first and second regions A1 and A2 are spaced apart.

The first pattern 323a and the second pattern 323b may be identical or similar in shape to each other. For example, the first pattern 323a and the second pattern 323b may have mirror image shapes or symmetrical arrangements based on the boundary between the first and second areas A1 and A2.

The first pattern 323a may face the first light source package 321 and include at least one first inclined plane a1 having a predetermined inclination angle with respect to a bottom surface of the first light guide plate 323. Similarly, the second pattern 323b may face the second light source package 322 and include at least one second inclined surface a2 having a predetermined inclination angle with respect to the bottom surface of the first light guide plate 323. In an embodiment, the inclination angle is about 30 ° to 50 °, and preferably 40 °, but is not limited thereto.

In the present embodiment, the cross sections of the first pattern 323a and the second pattern 323b may be asymmetric trapezoid shapes with the inclined surfaces a1 and a2 as sides. However, the outline is not limited to the present embodiment, and the cross sections of the first pattern 323a and the second pattern 323b may have various shapes, such as an asymmetric triangle or a polygon with the above-described inclined surfaces a1 and a2 as sides.

The first pattern 323a and the second pattern 323b are spaced apart at similar intervals, and may have an elongated shape extending parallel to sides adjacent to the light source packages 321 and 322. However, not limited to the present embodiment, the first pattern 323a and the second pattern 323b may have long or short stripes or dots arranged to be regularly or irregularly spaced or dispersed.

In the embodiment of fig. 9 and 10, the first backlight unit 320 may further include a fourth light source package 324. The fourth light source packages 324 may be disposed on a side of the first light guide plate 323 where the first and second light source packages 321 and 322 are not disposed. For example, the fourth light source package 324 may be disposed on a side of the third region A3 where the first and second patterns 323a and 323b are not formed.

Light generated from the fourth light source package 324 may be guided through the first light guide plate 323 and emitted through the top surface in the third region A3. Since the guide path is not blocked by the first pattern 323a or the second pattern 323b, light emitted from the fourth light source package 324 may be always emitted through the top surface in the central region. Accordingly, by using the fourth light source package 324, it is possible to control the mode so that an image can be displayed in the center area of the display panel 110. For example, by adding the fourth light source package 324, a controller in the display device 3 may selectively control the display device 3 to operate in six different display modes, which will be described in more detail below.

Fig. 11 to 16 are cross-sectional views illustrating various modes of a display device according to another embodiment. In fig. 11 to 16, the fourth light source package 324 is not depicted for convenience of explanation.

In the embodiment of fig. 11 to 16, the display device 1 is mounted in a vehicle. The display device 1 may be integrally or detachably mounted on a dashboard or center console of the vehicle. Particularly in the present embodiment, the display device 3 may be mounted on the instrument panel in an area other than the front face of the driver's seat in which the instrument panel is displayed.

In an embodiment, the display device 3 may display a Graphical User Interface (GUI) corresponding to navigation, video content, and audio content in response to a driving state and/or a user request.

Specifically, the display device 3 may operate in the privacy viewing mode while the vehicle is running. For example, the display device 3 may operate in the privacy viewing mode when displaying video or other content that is considered to distract the user while driving. In contrast, the display device 3 may operate in the shared viewing mode during the non-driving period of the vehicle. The display device 3 can be operated in the shared viewing mode even when the vehicle is operating. For example, when displaying a video (such as navigation) that is considered to be helpful for the user to drive, the display apparatus 3 may operate in the shared viewing mode.

Referring to part (a) of fig. 11, when the display device 3 operates in the first mode, the first and second light source packages 321 and 322 of the first backlight unit 320 are turned on. In addition, the fourth light source package 324 of the first backlight unit 320 may be turned on. The third light source package 331 of the second backlight unit 330 may be turned off.

Light generated from the first light source package 321 is guided to the first area A1 through the first light guide plate 323, and is blocked from entering the second area A2 by the first pattern 323 a. Similarly, light generated from the second light source package 322 is guided to the second area A2 through the first light guide plate 323, and is blocked from entering the first area A1 by the second pattern 323 b.

As a result, light generated from the first and second light source packages 321 and 322 is emitted through the top surfaces in both the first and second areas A1 and A2. The light generated from the fourth light source package 324 may be guided through the first light guide plate 323 and emitted through the top surface in the third area A3 as a central area. As a result, an image may be output through the entire area of the first display panel 310.

In this way, when the first and second light source packages 321 and 322 are turned on, a shared viewing mode can be realized such that the viewing angle is opened to the entire front and side of the display device 3, as shown in part (b) of fig. 11. In the shared viewing mode, the user in both the driver seat and the passenger seat can view all the images displayed on the entire area of the display device 3. For example, the first display area A1, the third display area A3, and the second display area A2 may all provide a wide viewing angle.

Referring to part (a) of fig. 12, when the display device 3 operates in the second mode, the third light source package 331 of the second backlight unit 330 is turned on. The first, second, and fourth light source packages 321, 322, and 324 of the first backlight unit 320 may be turned off.

The light generated from the third light source package 331 may be guided through the second light guide plate 332 and emitted through the top surface of the second light guide plate 332. The emitted light may be controlled within a narrow angle range by the light shielding pattern 342, passing through the light path control pattern 340. As a result, as shown in part (b) of fig. 12, a first privacy mode can be realized in which the viewing angle of the front face of the display device 3 is open, while the viewing angle of the side face is limited. For example, the first display area A1, the third display area A3, and the second display area A2 may all provide a narrow viewing angle.

In the first privacy mode, the users in both the driver's seat and the passenger's seat can only view the images displayed on their front display device 3. That is, the user in the driver seat can only view a part of the image (e.g., navigation, instrument panel, etc.) displayed on the display device 3 from the front surface of the driver seat.

Referring to part (a) of fig. 13, when the display device 3 operates in the third mode, the second and fourth light source packages 322 and 324 of the first backlight unit 320 and the third light source package 331 of the second backlight unit 330 are turned on. The first light source package 321 of the first backlight unit 320 may be turned off.

Light generated from the second light source package 322 is guided to the second area A2 through the first light guide plate 323, and is prevented from being guided to the first area A1. Accordingly, the light generated from the second light source package 322 is emitted through the top surface in the second region A2. Light generated from the fourth light source package 324 may be guided through the first light guide plate 323 and emitted through the top surface in the third area A3 as a central area. Accordingly, as shown in part (b) of fig. 13, in the second and third areas A2 and A3, the viewing angles of the front and side surfaces of the display device 3 can be completely opened.

The light generated from the third light source package 331 may be guided through the second light guide plate 332 and emitted through the top surface of the second light guide plate 332. The emitted light may be controlled within a narrow viewing angle range by the light shielding pattern 342, passing through the light path control pattern 340. As a result, in the first area A1, the viewing angle of the front face of the display device 3 may be open, while the viewing angle of the side face may be limited.

Accordingly, the third mode is a partial privacy mode (third privacy mode) in which the display device 3 can operate such that the privacy mode is implemented only in the first area A1, and the third area A3 and the second area A2 can operate in the wide view angle mode or the sharing mode.

Referring to part (a) of fig. 14, when the display device 3 operates in the fourth mode, the first and second light source packages 321 and 322 of the first backlight unit 320 and the third light source package 331 of the second backlight unit 120 are turned on. The fourth light source package 324 of the first backlight unit 320 may be turned off.

Light generated from the first light source package 321 is guided to the first area A1 through the first light guide plate 323, and is blocked from being guided to the second area A2 by the first pattern 323 a. Similarly, light generated from the second light source package 322 is guided to the second area A2 through the first light guide plate 323, and is blocked from entering the first area A1 by the second pattern 323 b.

As a result, light generated from the first and second light source packages 321 and 322 is emitted through the top surfaces in both the first and second areas A1 and A2.

The light generated from the third light source package 331 may be guided through the second light guide plate 332 and emitted through the top surface of the second light guide plate 332. The emitted light may be controlled within a narrow angle range by the light shielding pattern 342, passing through the light path control pattern 340. Accordingly, as shown in part (b) of fig. 14, in the third area A3, the viewing angle of the front face of the display device 3 may be open, while the viewing angle of the side face may be limited.

Thus, the fourth mode is a partial privacy mode (fourth privacy mode) in which the display device 4 is operable such that the privacy mode is implemented only in the second area A3. For example, the third area A3 may provide a narrow viewing angle, and the first and second areas A1 and A2 may provide a wide viewing angle.

Referring to part (a) of fig. 15, when the display device 3 operates in the fifth mode, the first and fourth light source packages 321 and 324 of the first backlight unit 320 and the third light source package 331 of the second backlight unit 120 are turned on. The second light source package 322 of the first backlight unit 320 may be turned off.

Light generated from the first light source package 321 is guided to the first area A1 through the first light guide plate 323, and prevented from entering the second area A2. Accordingly, light emitted from the first light source package 321 is emitted through the top surface in the second region A1. Light generated from the fourth light source package 324 may be guided through the first light guide plate 323 and emitted through the top surface in the third area A3 as a central area. Accordingly, in the first and third areas A1 and A3, the viewing angle can be completely opened to the front and side of the display device 1.

The light generated from the third light source package 331 may be guided through the second light guide plate 332 and emitted through the top surface of the second light guide plate 332. The emitted light may be controlled within a narrow viewing angle range by the light shielding pattern 342, passing through the light path control pattern 340. Accordingly, as shown in part (b) of fig. 15, in the second area A2, the viewing angle of the front face of the display device 3 may be open, while the viewing angle of the side face may be limited.

Accordingly, the fifth mode is a partial privacy mode (fifth privacy mode) in which the display device 3 is operable so that the privacy mode is implemented only in the second area A2. For example, the first and third areas A1 and A3 may provide a wide viewing angle, and the second area A2 provides a narrow viewing angle.

Referring to part (a) of fig. 16, when the display device 3 operates in the sixth mode, the fourth light source packages 324 of the first backlight unit 320 and the third light source packages 331 of the second backlight unit 120 are turned on. The first and second light source packages 321 and 322 of the first backlight unit 320 may be turned off.

Light generated from the fourth light source package 324 may be guided through the first light guide plate 323 and emitted through the top surface in the third area A3 as a central area. Accordingly, in the third area A3, the viewing angle can be completely opened to the front and side of the display device 3.

The light generated from the third light source package 331 may be guided through the second light guide plate 332 and emitted through the top surface of the second light guide plate 332. The emitted light may be controlled within a narrow viewing angle range by the light shielding pattern 342, passing through the light path control pattern 340. Accordingly, as shown in part (b) of fig. 16, in the first and second areas A1 and A2, the viewing angle of the front face of the display device 3 may be open, and the viewing angle of the side face may be limited.

Accordingly, the sixth mode is a partial privacy mode (sixth privacy mode) in which the display device 3 is operable such that the privacy mode is implemented only in the first and second areas A1 and A2. For example, the first and second areas A1 and A2 may provide a narrow viewing angle, and the third area A3 provides a wide viewing angle.

Furthermore, according to another embodiment, the display device 3 may provide a high brightness mode, wherein the first light source package 121, the second light source package 122, the third light source package 131 and the fourth light source package 324 are all turned on simultaneously (e.g. when the ambient light is bright, such as in a sunny day or in an emergency, etc., which may be helpful).

Fig. 17 is a cross-sectional view schematically showing the structure of a first backlight unit according to another embodiment. The display device 4 according to the embodiment of fig. 17 is identical to the display device according to the embodiment of fig. 1 except for the structure of the first light guide plate 433. Therefore, detailed descriptions of the same or overlapping components as those in the embodiment of fig. 1 are omitted.

Referring to fig. 17, the first backlight unit 420 may include a first light source package 421, a second light source package 422, and a first light guide plate 423.

The first light guide plate 423 is interposed between the first and second light source packages 421 and 422. The first light guide plate 423 is disposed between the first and second light source packages 421 and 422, facing the first and second light source packages 421 and 422, to guide light incident from the first and second light source packages 421 and 422 and emit light through the top surface.

The first light guide plate 423 may include first and second patterns 423a and 423b protruding from a bottom surface thereof. The first pattern 423a and the second pattern 423b may be formed in a relief manner on the bottom surface of the first light guide plate 423 by a molding or printing method.

In an embodiment, the first pattern 423a and the second pattern 423b may be formed on the entire bottom surface of the first light guide plate 423 or in at least one region. For example, the first pattern 423a may be formed in a first region A1 adjacent to the first light source package 421 on the first light guide plate 423. The second pattern 423b may be formed in a second region A2 adjacent to the second light source package 422 on the first light guide plate 423. Here, the first pattern 423a and the second pattern 423b may be disposed adjacent to each other at a boundary between the first and second areas A1 and A2.

The first pattern 423a and the second pattern 423b may be identical or similar in shape to each other. For example, the first pattern 423a and the second pattern 423b may have mirror image shapes or symmetrical arrangements based on boundaries between the first and second areas A1 and A2.

The first pattern 423a may face the first light source package 421 and include at least one first inclined plane a1 having a predetermined inclination angle with the bottom surface of the first light guide plate 423. Similarly, the second pattern 423b may include at least one second inclined plane a2 facing the second light source package 422 and having a predetermined inclination angle with the bottom surface of the first light guide plate 423. In an embodiment, the inclination angle is about 30 ° to 50 °, preferably 40 °, but is not limited thereto.

In the present embodiment, the cross sections of the first and second patterns 423a and 423b may be asymmetric trapezoids having the above-described inclined planes a1 and a2 as the vertical sides. However, the outline is not limited to the present embodiment, and the cross sections of the first pattern 423a and the second pattern 423b may have various shapes, such as an asymmetric triangle or a polygon having the above-described inclined surfaces a1 and a2 as sides.

The first and second patterns 423a and 423b are spaced apart at similar intervals, and may have an elongated shape extending parallel to sides adjacent to the light source packages 421 and 422. However, not limited to the present embodiment, the first pattern 423a and the second pattern 423b may have long or short stripes or dots arranged to be regularly or irregularly spaced or dispersed.

In the embodiment of fig. 17, the first light guide plate 423 may further include a fourth pattern 423d protruding from a top surface of the first light guide plate 423. The third pattern 423d may be formed in a relief manner on the top surface of the first light guide plate 423 by a molding or printing method.

The fourth pattern 423d may be formed on the entire top surface of the first light guide plate 423 or in at least one region. For example, the fourth pattern 423d may be formed in a central region on the top surface of the first light guide plate 423.

The fourth pattern 423d may be a lens having a dome shape or a hemispherical shape, the cross section of which is semicircular. The fourth pattern 423d may collect and disperse light emitted from the first light guide plate 423 toward the front and side surfaces of the central region. As a result, it is possible to improve the discontinuous image perception problem perceived by the viewer at the boundary between the first and second areas A1 and A2 caused by the blocking of the first and second patterns 423a and 423b of the light guide.

Meanwhile, in the embodiment of fig. 17, the first light guide plate 423 is formed to have a variable thickness. For example, the first light guide plate 423 may be formed to have the thickest thickness at edges adjacent to the first and second light source packages 421 and 422 and gradually decrease toward the central region (e.g., an inverted trapezoidal shape). Such thickness variation may enable better blocking of light emitted from the first light source package 421 from being directed toward the second region A2, and blocking of light emitted from the second light source package 422 from being directed toward the first region A1.

The backlight unit and the display device including the same according to the embodiments can effectively control the viewing angle by forming an asymmetric pattern on the bottom surface of the light guide plate of the upper backlight unit among the plurality of backlight units constituting the display device.

The backlight unit and the display apparatus including the same according to the embodiments can improve the cut-off efficiency limiting the viewing of the driver, while allowing the driver to view an image with enhanced brightness when necessary, and selectively provide different viewing modes that can selectively provide different viewing angles for different regions of the display screen.

The backlight unit and the display device including the same according to the embodiments can control the range of viewing angles and the cut-off efficiency by adjusting the size, height, and side angle of the pattern having the asymmetric shape.

Those skilled in the art to which the present invention pertains will appreciate that the present invention may be embodied in other specific forms without changing its technical spirit or essential characteristics. Accordingly, it should be understood that the above-described embodiments are illustrative in all respects, rather than restrictive. The scope of the invention should be determined by the appended claims rather than the foregoing detailed description, and all changes or modifications that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. A backlight unit, comprising:

a first light source package configured to output light;

a second light source package configured to output light, the second light source package facing the first light source package; and

A light guide plate disposed between the first light source package and the second light source package, the light guide plate including a pattern protruding from a bottom surface of the light guide plate,

Wherein the pattern faces the first light source package or the second light source package and includes at least one inclined surface having an inclination angle with respect to the bottom surface of the light guide plate.

2. The backlight unit of claim 1, wherein the pattern comprises:

A first pattern disposed in a first region adjacent to the first light source package, the first pattern including a first slope facing the first light source package; and

And a second pattern disposed in a second region adjacent to the second light source package, the second pattern including a second slope facing the second light source package.

3. The backlight unit of claim 2, wherein the first pattern and the second pattern have a symmetrical arrangement or a mirrored configuration based on a boundary between the first region and the second region.

4. The backlight unit according to claim 2, wherein a cross section of each of the first pattern and the second pattern has an asymmetric trapezoidal shape.

5. The backlight unit of claim 2, wherein the first slope of the first pattern is configured to refract the light output from the first light source package to be emitted in the first region through a top surface of the light guide plate; and

Wherein the second slope of the second pattern is configured to refract the light output from the second light source package to be emitted in the second region through the top surface of the light guide plate.

6. The backlight unit according to claim 2, wherein the first and second regions are adjacent to each other, and the first and second patterns are arranged adjacent to each other at a boundary between the first and second regions.

7. The backlight unit according to claim 2, further comprising a third light source package disposed on one side of the third region,

Wherein the first region and the second region are spaced apart from each other,

Wherein the third region is formed between the first region and the second region, and the first pattern and the second pattern are spaced apart from each other,

Wherein the pattern further includes a third pattern disposed in the third region, the third pattern including a third slope facing the first light source package or the second light source package, and

Wherein each of the third inclined surfaces has an inclination angle smaller than those of the first inclined surface and the second inclined surface.

8. The backlight unit of claim 2, further comprising fourth patterns protruding from a top surface of the light guide plate, each of the fourth patterns having a dome shape or a hemispherical shape.

9. The backlight unit of claim 1, wherein a central portion of the light guide plate is thinner than portions of the light guide plate adjacent to the first and second light source packages.

10. A display device, comprising:

A display panel configured to display an image;

a first backlight unit disposed under the display panel and configured to emit light to the display panel;

A second backlight unit disposed under the first backlight unit and configured to emit light to the display panel; and

An optical path control pattern disposed between the first and second backlight units, the optical path control pattern including a light shielding pattern configured to control the light emitted from the second backlight unit to be emitted toward the display panel at a narrow viewing angle,

Wherein the first backlight unit includes:

a first light source package configured to output light;

A first light guide plate disposed between the first light source package and the second light source package, the first light guide plate including a pattern protruding from a bottom surface of the first light guide plate,

Wherein each of the patterns includes at least one slope facing the first light source package or the second light source package.

11. The display device according to claim 10, further comprising:

a third light source package configured to output light; and

And a second light guide plate disposed on one side of the third light source package.

12. The display device of claim 11, wherein the pattern comprises:

13. The display device of claim 12, wherein the first slope of the first pattern is configured to refract the light output from the first light source package to be emitted in the first region through a top surface of the light guide plate,

Wherein the second slope of the second pattern is configured to refract the light output from the second light source package to be emitted in the second region through the top surface of the light guide plate, and

Wherein the second light guide plate is configured to guide the light output from the third light source package through a top surface of the second light guide plate, and the light path control pattern is configured to control the light output through the top surface of the second light guide plate to be emitted toward the display panel at a narrow viewing angle in the first and second regions.

14. The display device of claim 12, further comprising a third region formed between the first region and the second region,

Wherein the first backlight unit further includes a fourth light source package disposed on one side of the third region, the fourth light source package configured to output light.

15. The display device of claim 14, wherein the first light guide plate is configured to guide light output from the fourth light source package to be emitted in the third region through the top surface of the first light guide plate.

16. The display device of claim 12, wherein the pattern further comprises a third pattern disposed in a third region between the first region and the second region, the third pattern comprising a third slope facing the first backlight unit or the second backlight unit.

17. The display device of claim 16, wherein each of the third inclined planes has an inclination angle smaller than an inclination angle of the first and second inclined planes.

18. A display device, comprising:

a display panel configured to display an image, the display panel including a first region and a second region;

a first backlight unit including a first light source package and a second light source package;

a second backlight unit including a third light source package;

an optical path control pattern disposed between the first and second backlight units, the optical path control pattern configured to guide light output from the second backlight unit toward the first backlight unit at a narrow viewing angle; and

A controller configured to:

In response to turning on both the first light source package and the second light source package and turning off the third light source package, displaying one or more images in the first region and the second region at a wide viewing angle based on a shared viewing mode; and

In response to turning off both the first light source package and the second light source package and turning on the third light source package, displaying one or more images in the first region and the second region at a narrow viewing angle based on a privacy viewing mode,

Wherein the wide viewing angle has a wider viewing angle than the narrow viewing angle.

19. The display device of claim 18, wherein the controller is further configured to:

In response to turning on one of the first light source package and the second light source package and turning on the third light source package, an image is displayed at a narrow viewing angle in the first region and an image is displayed at a wide viewing angle in the second region based on a mixed viewing mode.

20. The display device of claim 18, wherein the first backlight unit comprises a first light guide plate,

Wherein the first light source packages and the second light source packages are disposed on opposite sides of the first light guide plate, wherein the first light guide plate includes patterns having slopes disposed between the first light source packages and the second light source packages, and wherein a cross section of each of the patterns includes a trapezoid shape.